JPH05272701A - Fluidized bed type boiler - Google Patents

Abstract

PURPOSE:To prevent a fluidized bed type boiler form being damaged and produce the boiler at a low cost by a method wherein a lower surface of an air box part of an air dispersion pipe is supported at an inlet header of a column for supporting the air dispersion pipe through a sliding seat. CONSTITUTION:An inner cylinder 27 of a hot air inlet cylinder part 7 is directly welded and fixed to an opening of an air box 9 of an air dispersion pipe 8 and both of them are completely sealed. Then, an inlet header 19 of a column for supporting the air dispersion pipe it fixed to an outer cylinder 29 having an expandable coupling 28 through a supporting member 20 and a lower surface of the air box 9 of the air dispersion pipe 8 is supported at an inlet header 19 of a column for supporting the air dispersion pipe through a sliding seat 34. With such an arrangement, vertical and horizontal displacement of a central part of the air dispersion pipe toward the air box is allowed. Accordingly, damage of the fluidized bed type boiler can be prevented and the boiler can be produced at a low cost.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fluidized bed boiler.

[0002]

2. Description of the Related Art FIGS. 6 and 7 are schematic views of a fluidized bed boiler, in which 1 is a fluidized bed boiler main body in which a bed material (not shown) is fluidized, and 2 is a fluidized bed boiler main body 1. Is a plurality of heat transfer tubes provided inside.

In the lower part of the fluidized bed boiler main body 1, hot gas from the starting burner 3 and air for combustion and bed material flow from the air supply pipe 4 are blown into the inside of the fluidized bed boiler main body 1. Air supply device 5 for flowing the material
Is provided.

The air supply device 5 has a wind box 6 connected to the start-up burner 3 and the air supply device 5, and a plurality of air boxes connected to the upper part of the air box 6 via hot air inlet cylinders 7, respectively. Each of the air diffusers 8 is composed of a central air box part 9 connected to each hot air inlet cylinder part 7, and an air diffuser branched from a plurality of ends of the air box part 9. It is configured by a portion 10, a wind box portion 9 of the air diffusing tube 8, and a plurality of air nozzles 11 provided on the upper surface of the air diffusing portion 10.

Further, as shown in FIG. 8, the hot air inlet cylindrical portion 7 is constituted by an inner cylinder 12 and an outer cylinder 14 on which an expansion portion 13 is formed, and is welded and fixed at a lower portion thereof. A heat insulating material 15 is interposed between the inner and outer cylinders 12 and 14.

The upper end of the hot air inlet cylindrical portion 7 and the air box portion 9 of the air diffusing tube 8 are separated from each other, and a seal member 16 is provided at the separated portion between the two, and the seal member 16 is composed of the inner cylinder 12 and the inner cylinder 12. A cylindrical body 17 fixed by welding and attached to the upper surface of the seal member 16 is slidably abutted horizontally in the opening of the air box portion 9 of the air diffuser 8. Further, the wind box portion 9 of the air diffuser 8 is formed with an expansion portion 18 for allowing the cylindrical body 17 to slide.

Further, an air diffuser support column inlet header 19 is attached near the upper end of the outer cylinder 14 of the hot air inlet cylindrical portion 7 via a support member 20, and the air diffuser support column inlet header 19 has A bolt 21 for fastening the cylindrical body 17 attached to the opening of the air diffuser 8 to the wind box 9 and the seal member 16 so that the seal member 16 can be sealed with almost no clearance.
Is fixed.

The upper end of the outer cylinder 14 of the hot air inlet cylinder 7 is
The groove 22 formed in the lower surface of the sealing member 16 is slidably fitted.

Further, the end of the air diffuser 10 of the air diffuser 8 is
As shown in FIG. 6, the header 24 is slidably supported in a horizontal direction via a slide support 23.

In the figure, 25 is a hopper provided below the air diffuser 10 of the air diffuser 8, and 26 is a heat insulating material interposed between the hopper 25 and the wind box 6.

At the time of starting the fluidized bed boiler, hot gas from the starter burner 3 and air for combustion and bed material flow from the air supply pipe 4 during operation of the fluidized bed boiler It is sent to the box 6, the hot air inlet cylindrical portion 7, the air box portion 9 of the air diffusing tube 8, and the air diffusing portion 10 of the air diffusing tube 8 in order, and a large number are provided on the air box portion 9 and the air diffusing portion 10 of the air diffusing tube 8. The bed material is blown into the inside of the fluidized-bed boiler main body 1 from the air nozzle 11 provided to make the bed material flow.

Further, the horizontal displacement of the air diffuser 8 due to thermal expansion separates the air box part 9 of the air diffuser 8 from the hot air inlet cylindrical part 7 and heats the cylindrical body 17 on the air box part 9 side. Air inlet cylinder 7
Side seal member 16 slidably in a horizontal direction, and an expansion part 18 is formed in the wind box part 9, and the air diffusing part 10 of the air diffusing tube 8 is attached to the header via a slide support 23. By allowing 24 to slide horizontally, it is allowed.

The seal between the cylindrical body 17 and the seal member 16 is secured by tightening bolts 21 for fastening the upper and lower surfaces of the wind box 9 of the air diffuser 8.

[0014]

However, the conventional fluidized bed boiler described above has the following problems.

That is, when the fluidized bed boiler is started, the temperature of the upper surface of the air diffusing tube 8 becomes higher than that of the lower surface thereof, and the thermal expansion of the air diffusing tube 8 becomes larger than that of the lower surface thereof. As shown in the figure, it is going to be deformed into a convex shape, but the upper and lower surfaces of the wind box part 9 of the air diffuser 8 are fastened with bolts 21, and the bolts 21 are fixed to the air diffuser support column inlet header 19. Since the central portion of the air diffuser 8 cannot be displaced in the vertical direction, a compression strain occurs on the upper surface side of the air diffuser 8 due to the difference in expansion due to the temperature difference between the upper and lower surfaces of the air diffuser 8 at the time of startup.
When the air diffuser 8 is exposed to a high temperature for a long time while having the compressive strain, the air diffuser 8 is deformed (creep deformation), and the original shape cannot be restored even when the temperature of the air diffuser 8 falls.

While the fluidized bed boiler is repeatedly started and stopped, the air diffuser 8 is deformed, the air diffuser 10 of the air diffuser 8 floats up from the slide support 23, and the air box of the air diffuser 8 is blown. 9 may cause damage such as cracking in the expansion part 18 and cause air leakage from the expansion part 18, resulting in wear of the surrounding pressure-resistant parts and the like, and poor distribution of air. was there.

In addition, the seal member 16 provided on the hot air inlet cylindrical portion 7 side has strict dimensional tolerances, and since the expansion portions 13 and 18 must be provided at each portion, the manufacturing cost is high. ..

In view of the above situation, it is an object of the present invention to provide a fluidized bed boiler that can prevent damage and can be manufactured at low cost.

[0019]

According to the present invention, a wind box 6 is provided below a fluidized bed boiler body 1, and a plurality of air diffusers 8 for supplying air for bed material flow into the fluidized bed boiler body 1.
In the fluidized bed boiler provided with the air supply device 5 including the air box 6 and the hot air inlet cylinder portion 7 connecting between the air diffuser tubes 8 and the like, the diffuser tube 8 has an inner cylinder 27 of the hot air inlet cylinder portion 7.
Is directly fixed by welding, and the expansion joint 28 is attached to the outer periphery of the inner cylinder 27.
The outer cylinder 29 having the inner cylinder 27
And the upper end of the outer cylinder 29 is separated from the inner cylinder 27. Further, the diffuser pipe support column inlet header 19 is fixed to the upper end of the outer cylinder 29, and the cylindrical portion 30 and the cylindrical portion 30 are fixed. Tapered portion 31 whose diameter decreases toward the upper end as it goes upward
Is provided, the tapered portion 31 of the slide member 32 is welded and fixed to the inner cylinder 27 of the hot air inlet cylindrical portion 7, and the cylindrical portion 30 of the slide member 32 is slidably fitted to the outer cylinder 29. Further, a slide seat 34 is provided on the top of the air diffuser support column inlet header 19 to fit the air diffuser 8
The present invention relates to a fluidized-bed boiler, which has a lower surface supported slidably in a horizontal direction.

[0020]

According to the present invention, the inner cylinder 27 of the hot air inlet cylinder portion 7 is directly welded and fixed to the opening of the air box portion 9 of the air diffusing pipe 8 to ensure the perfect sealing property between the two.

Then, the air diffusion pipe supporting column inlet header 19 is provided to the outer cylinder 29 having the expansion joint 28 via the supporting member 20.
Is fixed and the lower surface of the air box portion 9 of the air diffuser tube 8 is supported by the air diffuser tube supporting column inlet header 19 via the slide seat 34, whereby the upward movement of the air box portion 9 at the center of the air diffuser tube 8 is allowed. To be done.

Further, by supporting the lower surface of the air box part 9 of the air diffuser 8 through the slide seat 34 on the air diffuser support column inlet header 19, the horizontal displacement of the air box part 9 at the center of the air diffuser 8 is achieved. Permissible.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 show an embodiment of the present invention.

Further, in the figure, the same components as those in FIGS. 6 to 8 are designated by the same reference numerals, and the description thereof will be omitted. Hereinafter, only the configuration unique to the present invention will be described.

The inner cylinder 27 of the hot air inlet cylinder 7 is welded and fixed to the opening of the air box 9 of the air diffuser 8 to form a welded airtight structure.

An outer cylinder 29 having an expansion joint 28 on the outer circumference of the inner cylinder 27 of the hot air inlet cylinder 7 with a heat insulating material 15 interposed therebetween.
And the lower end of the outer cylinder 29 is welded and fixed to the inner cylinder 27, the upper end of the outer cylinder 29 is separated from the inner cylinder 27, and the upper end of the outer cylinder 29 is supported by the support member 20 through the air diffuser support column. The inlet header 19 is fixed by welding.

The cylindrical portion 30 and the cylindrical portion 30
A slide member 32 made of spring steel having a taper portion 31 whose diameter decreases as it goes upward is provided at the upper end.
2 is interposed between the inner cylinder 27 of the hot air inlet cylindrical portion 7 and the upper end of the outer cylinder 29, the taper portion 31 of the slide member 32 is welded and fixed to the inner cylinder 27, and the slide member 32 is fixed to the outer cylinder 29. The cylindrical portion 30 is slidably fitted inside.

The taper portion 31 of the slide member 32 is
The slits 33 are formed radially.

Further, a slide seat 34 is provided above the air diffuser support column inlet header 19 to support the lower surface of the air box part 9 of the air diffuser 8 slidably in the horizontal direction.

Reference numeral 35 is a dispersion plate provided above the opening of the air box portion 9 of the air diffusing tube 8, and 36 is a connecting tube for connecting between the air diffusing tube supporting column inlet headers 19.

Next, the operation will be described.

The process of supplying hot gas from the start-up burner 3 and air for combustion and bed material flow from the air supply pipe 4 to the fluidized bed boiler main body 1 is the same as in FIGS. Is omitted.

In the present invention, the inner cylinder 27 of the hot air inlet cylindrical portion 7 is directly welded and fixed to the opening of the air box portion 9 of the air diffusing tube 8 to ensure a perfect seal between them.

Then, the diffuser pipe support column inlet header 19 is provided to the outer cylinder 29 having the expansion joint 28 via the support member 20.
Is fixed and the lower surface of the air box portion 9 of the air diffuser tube 8 is supported by the air diffuser tube support column inlet header 19 via the slide seat 34 to allow upward displacement of the air box portion 9 at the center of the air diffuser tube 8. is doing.

Further, by supporting the lower surface of the air box part 9 of the air diffuser 8 via the slide seat 34 on the air diffuser support column inlet header 19, the horizontal displacement of the air box part 9 at the center of the air diffuser 8 is achieved. Tolerate.

The displacement of the air diffuser 10 of the air diffuser 8 in the horizontal direction is allowed by the slide support 23 as in FIGS. 6 to 8.

As described above, the inner cylinder 27 of the hot air inlet cylindrical portion 7 is directly welded and fixed to the opening of the air box portion 9 of the air diffuser 8 to secure the sealing property between the two, and the wind at the center of the air diffuser 8 is secured. By adopting a structure that allows the box portion 9 to be displaced in the vertical direction, damage due to deformation of the air diffuser 8 is prevented.

Further, by adopting the above-mentioned structure, the seal member 16 (see FIG. 8) having strict dimensional tolerances,
Since various expansion parts 13 and 18 are unnecessary,
The cost of the device can be reduced.

The present invention is not limited to the above-described embodiments, but can be applied to various fluidized bed boilers such as a pressurized fluidized bed boiler, and the scope of the present invention is not deviated. Of course, various changes can be made within.

[0041]

As described above, according to the fluidized bed boiler of the present invention, the excellent effects of preventing damage and achieving low cost can be obtained.

[Brief description of drawings]

FIG. 1 is a partially enlarged side view in which a part of an embodiment of the present invention is cut away.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a plan view of FIG.

FIG. 4 is a view taken along the line IV-IV in FIG.

5 is a plan view of the slide member of FIG. 1. FIG.

FIG. 6 is a schematic side sectional view of a fluidized bed boiler in a conventional example.

7 is a view taken along the line VII-VII in FIG.

FIG. 8 is a partially enlarged view of FIG.

[Explanation of symbols]

 7 Hot Air Inlet Cylindrical Section 8 Air Diffusing Tube 19 Air Diffusing Tube Support Column Inlet Header 27 Inner Cylinder 28 Expansion Joint 29 Outer Cylinder 30 Cylindrical Section 31 Tapered Section 32 Sliding Member 34 Sliding Seat

Claims (1)

[Claims] 1. A wind box 6 is provided at the bottom of the fluidized bed boiler body 1.
A plurality of air diffusing tubes 8 for supplying air for flowing the bed material into the fluidized bed boiler body 1, the wind box 6 and each air diffusing tube 8
In a fluidized bed boiler provided with an air supply device 5 including a hot air inlet cylinder portion 7 and the like connecting between them, the inner cylinder 27 of the hot air inlet cylinder portion 7 is directly welded and fixed to the air diffusing pipe 8, and the inner cylinder 27 An outer cylinder 29 having an expansion joint 28 is arranged on the outer circumference of the outer cylinder 29, and the lower end of the outer cylinder 29 is welded and fixed to the inner cylinder 27.
The upper end of the outer cylinder 29 is separated from the inner cylinder 27, and the outer cylinder 2
Fix the diffuser tube support column inlet header 19 to the upper end of 9,
In addition, the slide member 3 having the cylindrical portion 30 and the taper portion 31 whose diameter decreases as it goes upward at the upper end of the cylindrical portion 30.
2 is provided, the taper portion 31 of the slide member 32 is welded and fixed to the inner cylinder 27 of the hot air inlet cylinder portion 7, and the outer cylinder 2
9, the cylindrical portion 30 of the slide member 32 is slidably fitted in the slide member 32, and a slide seat 34 is provided on the upper portion of the diffuser tube support column inlet header 19 to support the lower surface of the diffuser tube 8 in a horizontally slidable manner. A fluidized bed boiler characterized in that